SU687548A1 - Inverter - Google Patents

Description

(54) INVERTER

The invention relates to electrical engineering and can be used in high-frequency installations for induction heating or in an electric drive requiring high speed and a wide range of voltage regulation on the load.

Nonsymmetric inverters used to convert direct current energy into alternating current energy 1, 2 are known.

Closest to the proposed invention, an unbalanced serial single-cell inverter containing serially connected charge and recharge thyristors connected to input pins, the common point of which is connected to a negative input terminal 2 through a series circuit of a capacitor, throttles and output pins.

The disadvantage of such an inverter is the small range of voltage regulation on the load.

The purpose of the invention is to extend the range of voltage regulation.

This is achieved by counter-parallel to the recharged inverter thyristor

a thyristor is connected to the driver, and the input is connected to the input; i a T-shaped LC filter is connected.

FIG. given the inverter circuit; in fig. 2 - diagram yukov inverter with a load, included in the chain of co, one () circuit; on {.) ig. 3 - charts of currents .iHBCpTopri with power, BK.iiOMciiHoii noc, ie, with s; icT04HUi o, pi.tanp.

The inverter contained; ardny 1. res.dary 2 and dio.t-splnya 3 thyristors, capacitor 4 oscillating -circuit circuits, throttle 5 oscillating circuits, load 6, T-shaped LC-filter, consisting of droplet 8 and additional

sat down 7, capacitor

10 meals. Points sodrossel 9, source

5 of the unity of the drawing drawing letters a, b, c, d, d, e.

2 (points a, e zaRassremim fig. J shorter).

At time ti on the secondary thyristor

0 3 control pulse is applied. Thyristor 3 opens i-; an oscillating circuit occurs, formed by a capacitor 4, a choke 5 and a load 6. The current flows through the circuit 4-5--6-3-4. At time 1g, determined by the required voltage at the load, a control pulse is applied to charge thyristor 1. The current is switched from the additional thyristor 3 to charge thyristor 1, the load 6 is connected to the power supply. Current flows through the circuit 8-7-1-4-5-6-8. After the charge of the capacitor 4 has finished, the current is interrupted - time tj. At time t4, a control pulse is applied to recharge thyristor 2, capacitor 4 is recharged along circuit 4-2-b-4-4, which ends at time ts.

At time t, a control pulse is applied to the additional thyristor 3. Next, the processes in the inverter are repeated.

Changing the turn-on time of charge thyristor 1 with respect to the moment of switching on the additional thyristor 3, it is possible to change the time of connecting the load 6 to the power supply, thus smoothly adjusting the output voltage.

Consider FIG. 1, 3 {points r and in shorted).

At the time ti, a control pulse is applied to the additional thyristor 3. The thyristor 3 opens and an oscillating circuit occurs, which is formed by a capacitor 4, a choke 5, the current flows through the circuit 4-5-3-4. Through the load, the charge current of the capacitor 8 of the filter flows through the circuit 10-6-810. At time t), determined by the voltage required on the load, a control pulse is applied to the charge thyristor 1, the current is switched from the additional thyristor 3 to the charge thyristor 1. The current flows through the load through circuit 10-6-7-1 -4-5-10. The filter capacitor 8 is discharged along circuit 8-7 -4-5-8. At the time ts, the capacitor 4 is charged to the maximum voltage and the current in the oscillating circuit changes direction. Thyristor 1 is turned off. In the interval of moments ij-tf, the charge current of the capacitor 8 of the filter flows through the circuit 10-6-8-10 through the load. At time t4, the recharging of the thyristor 2 is turned on and the capacitor 4 is recharged along the circuit 4-2-5-4. At time ts, recharge d terminates. At time te, a control pulse is applied to the additional thyristor 3.

Further, the processes in the inverter are repeated. Thus, by turning on the load in series with the power source and changing the turn-on time of the charge thyristor 1 with respect to the moment when the additional thyristor 3 is turned on, the DC voltage on the load can be smoothly changed.

Claims (2)

1.Berkovich E.I. and others. Thyristor converters of high frequency.-L .: Energie, 1973, p. 46, fig. 3-16 days 2. Bedford B., Hoft R. Theory of autonomous inverters. - M .: Energie, 1969, p. 58, fig. 3-1. -CZb four V L / one five ; 2 tf / five/ P T t2 7 ts / is 5 if 7 tji